Solid-phase bonding of metals

Claim 1

THE METHOD OF SOLID-PHASE BONDING MALLEABLE METAL PIECES WHICH HAVE BEEN CLEANED THROUGHOUT THEIR SURFACES WHICH ARE TO BE BONDED, WHICH HAVE AT LEAST ONE OF SAID SURFACES WORK HARDENED AND WHICH HAVE SAID SURFACES PLACED IN CONTACT; COMPRISING, FIRST, SIMULTANEOUSLY HEATING AND PRESSING TOGETHER THE METALS, THE PRESSURE DURING SAID PRESSING AND HEATING BEING SUFFICIENT TO EFFECT SUBSTANTIALLY THROUGH THE BONDING AREA A MULTIDUDE OF DISCRETE CONTACTS, SAID HEATING BEING AT A TEMPERATURE LYING WITHIN THE RANGE WHICH EXTENDS FROM AND INCLUDES THE RECRYSTALLIZATION TEMPERATURE OF THE ONE OF THE METALS WHICH HAS BEEN WORK HARDENED, OR IF THERE BE MORE THAN ONE WORK-HARDENED METAL THEN FROM AND INCLUDING THE RECRYSTALLIZATION TEMPERATURE OF THE ONE WHICH HAS THE HIGHEST RECRYSTALLIZATION TEMPERATURE, AND IN EITHER CASE UP TO BUT NOT INCLUDING THE TEMPERATURE AT WHICH A LIQUID-PHASE OR BRITTLE INTERMETALLIC COMPOUND WOULD APPEAR IN THE BONDING AREA, IN ORDER TO CREATE A FIRST PARTIAL BOND BETWEEN THE METALS THROUGHOUT SAID AREA, SECOND, SEQUEEZING THE PARTIALLY BONDED METALS AT A TEMPERATURE BELOW THE RECRYSTALLIZATION TEMPERATURE OF THAT ONE OF THE METALS HAVING THE HIGHEST RECRYSTALLIZATION TEMPERATURE, SAID SQUEEZING BEING CARRIED OUT WITH A SUBSTANTIAL REDUCTION OF THE COMBINED THICKNESS OF THE METALS WITH A CONCOMITANT SUBSTANTIAL INCREASE IN THE BONDING AREA, IN ORDER TO RE-ENERGIZE THE INTERFACE; AND, THIRD, HEATING THE METALS AT A TEMPERATURE WHICH WILL RECRYSTALLIZE AT LEAST ONE OF THE METALS, BUT BELOW ONE OF THOSE TEMPERATURES, WHICHEVER IS THE LOWER, AS THE CASE MAY BE, AT WHICH LIQUID-PHASE MATERIAL OR A BRITTLE INTERMETALLIC COMPOUND WOULD FORM IN APPRECIABLE AMOUNT, SAID HEATING BEING CONTINUED FOR SUCH A TIME AS TO EFFECT GROWTH OF THE PARTIAL BOND, THEREBY SUBSTANTIALLY TO INCREASE THE OVER-ALL BOND STRENGTH.

Claim 2

THE METHOD OF SOLID-PHASE BONDING MALLEABLE METAL PIECES WHICH HAVE BEEN CLEANED THROUGHOUT THEIR SURFACES WHICH ARE TO BE BONDED, WHICH HAVE AT LEAST ONE OF SAID SURFACES WORK HARDENED AND WHICH HAVE SAID SURFACES PLACED IN CONTACT; COMPRISING, FIRST, SIMULTANEOUSLY HEATING AND PRESSING TOGETHER THE METALS, THE PRESSURE DURING SAID PRESSING AND HEATING BEING SUFFICIENT TO EFFECT SUBSTANTIALLY THROUGH THE BONDING AREA A MULTIDUDE OF DISCRETE CONTACTS, SAID HEATING BEING AT A TEMPERATURE LYING WITHIN THE RANGE WHICH EXTENDS FROM AND INCLUDES THE RECRYSTALLIZATION TEMPERATURE OF THE ONE OF THE METALS WHICH HAS BEEN WORK HARDENED, OR IF THERE BE MORE THAN ONE WORK-HARDENED METAL THEN FROM AND INCLUDING THE RECRYSTALLIZATION TEMPERATURE OF THE ONE WHICH HAS THE HIGHEST RECRYSTALLIZATION TEMPERATURE, AND IN EITHER CASE UP TO BUT NOT INCLUDING THE TEMPERATURE AT WHICH A LIQUID-PHASE OR BRITTLE INTERMETALLIC COMPOUND WOULD APPEAR IN THE BONDING AREA, IN ORDER TO CREATE A FIRST PARTIAL BOND BETWEEN THE METALS THROUGHOUT SAID AREA, SECOND, SEQUEEZING THE PARTIALLY BONDED METALS AT A TEMPERATURE BELOW THE RECRYSTALLIZATION TEMPERATURE OF THAT ONE OF THE METALS HAVING THE HIGHEST RECRYSTALLIZATION TEMPERATURE, SAID SQUEEZING BEING CARRIED OUT WITH A SUBSTANTIAL REDUCTION OF THE COMBINED THICKNESS OF THE METALS WITH A CONCOMITANT SUBSTANTIAL INCREASE IN THE BONDING AREA, IN ORDER TO RE-ENERGIZE THE INTERFACE; AND, THIRD, HEATING THE METALS AT A TEMPERATURE WHICH WILL RECRYSTALLIZE AT LEAST ONE OF THE METALS, BUT BELOW ONE OF THOSE TEMPERATURES, WHICHEVER IS THE LOWER, AS THE CASE MAY BE, AT WHICH LIQUID-PHASE MATERIAL OR A BRITTLE INTERMETALLIC COMPOUND WOULD FORM IN APPRECIABLE AMOUNT, SAID HEATING BEING CONTINUED FOR SUCH A TIME AS TO EFFECT GROWTH OF THE PARTIAL BOND, THEREBY SUBSTANTIALLY TO INCREASE THE OVER-ALL BOND STRENGTH.